Future warming threatens many marine organisms; among these are large benthic foraminifera. These symbiont-bearing protists are major carbonate producers and ecosystem engineers. To assess the relative contribution of host and symbiont algae to the holobiont thermal tolerance, we evaluated the calcification rate and photosynthetic activity under future warming scenarios.

Biomass-based terrestrial negative emission technologies (tNETS) have high potential to sequester CO2. Many CO2 uptake estimates do not include the effect of nutrient deficiencies in soils on biomass production. We show that nutrients can be partly resupplied by enhanced weathering (EW) rock powder application, increasing the effectiveness of tNETs. Depending on the deployed amounts of rock powder, EW could also improve soil hydrology, adding a new dimension to the coupling of tNETs with EW.

Climate variations can have profound impacts on marine ecosystems. Here we show that on global scales marine ecosystem drivers such as temperature, pH, O2 and NPP are potentially predictable 3 (at the surface) and more than 10 years (subsurface) in advance. However, there are distinct regional differences in the potential predictability of these drivers. Our study suggests that physical–biogeochemical forecast systems have considerable potential for use in marine resource management.

Ocean deoxygenation and warming are observed and projected to intensify under continued greenhouse gas emissions. Whereas temperature is considered the main climate change indicator, we show that in certain regions, thermocline doxygenation may be detectable before warming.

Analysing the impact of environmental changes due to climate change, e.g. geographical spread of climate-sensitive infections (CSIs) and agriculture crop modelling, may require land surface modelling (LSM) to predict future land surface conditions. There are multiple LSMs to choose from. The paper proposes a multivariate spatio-temporal data science method to understand the inherent uncertainties in four LSMs and the variations between them in Nordic areas for the net primary production.

Marine micro-algae bind carbon dioxide, CO2. During their decay, snowflake-like aggregates form that sink, remineralize and transport organically bound CO2 to depth; this is referred to as the biological carbon pump. In our model study, we elucidate how variable aggregate composition impacts the global pattern of vertical carbon fluxes. Our mechanistic model approach advances the representation of the global biological carbon pump and promotes a more realistic projection under climate change.

This study compares the climatic conditions and ecosystem response of the extreme European drought of 2018 with the previous extreme drought of 2003. Using gridded climate data and satellite-based remote sensing information, our analyses qualify 2018 as the new European record drought with wide-ranging negative impacts on European ecosystems. Given the observation of forest-legacy effects in 2019 we call for Europe-wide forest monitoring to assess forest vulnerability to climate change.

Due to the high elevation, the Tibetan Plateau (TP) is affected more strongly than the global average by climate warming. As a result of increasing air temperature, several environmental processes have accelerated, such as melting glaciers, thawing permafrost and grassland degradation. We review several modern and paleoenvironmental changes forced by climate warming in the lake system of Nam Co to shape our understanding of global warming effects on current and future geobiodiversity.

We analysed the ability of 34 climate models to reproduce main factors affecting the coccolithophore Emiliania huxleyi blooms in six Arctic and sub-Arctic seas. Furthermore, we proposed a procedure of ranking and selecting these models based on the model’s skill in reproducing 10 important oceanographic, meteorological, and biochemical variables in comparison with observation data and demonstrated that the proposed methodology shows a better result than commonly used all-model averaging.

Vertical migration of zooplankton has rarely been studied under the effect of a variable community structure, which depending on the behavior and size of its groups can strongly alter the magnitude of C being actively taken to depth by migrants. Here, we address this issue in a highly productive upwelling system, where a high amount of zooplankton can daily move below the mixed layer despite presence of an extremely low–oxygen water and so contribute to a significant export of C to depth.

We investigated the effects of ocean acidification (OA) on the production of climate active gas dimethylsulfide (DMS) in polar waters. We found that polar DMS production was unaffected by OA – in contrast to temperate waters, where large increases in DMS occurred. The regional differences in DMS response may reflect natural variability in community adaptation to ambient carbonate chemistry and should be taken into account in predicting the influence of future DMS emissions on Earth's climate.

Carbon stocks and dynamics are both uncertain in tropical forests, especially in Asia. We here quantify the carbon stock and recovery rate of a Thai landscape using airborne lidar and four decades of Landsat data. We show that the landscape has a high carbon stock despite its disturbance history and that secondary forests are accumulating carbon at high rate. Our study shows the potential synergy of remote sensing and field data to characterize the carbon dynamics of tropical forests.

Weathering is a major control on atmospheric CO2 at geologic timescales. Enhancement of this process can be used to actively remove CO2 from the atmosphere. Field results are still scarce and with this experiment we try to add some near-natural insights into dissolution processes. Results show CO2 sequestration potentials but also highlight the strong variability of outcomes that can be expected in natural environments. Such experiments are of the utmost importance to identify key processes.

In shade-tolerant tree species, growth is not strictly related to tree age. In this study we show that novel tree ring standardization models that incorporate tree size in the year of ring formation produce more accurate chronologies than those produced by contemporary, age-based standardization models. These findings are important for accurate and reliable long-term trend reconstruction in tree ring studies in all species but are especially so for shade-tolerant species.

We reconstructed environmental changes in the Öresund during the last 200 years, using foraminifera (microfossils), sediment, and climate data. Five zones were identified, reflecting oxygen, salinity, food content, and pollution levels for each period. The largest changes occurred ~ 1950, towards stronger currents. The foraminifera responded quickly (

Is the fraction of anthropogenically released CO2 that remains in the atmosphere increasing? Is the rate at which the ocean and land sinks take up CO2 from the atmosphere decreasing? We analyse these questions by means of a statistical dynamic multivariate model from which we estimate the unobserved trend processes together with the parameters that govern them. We find no statistical evidence of an increasing airborne fraction, but we do find statistical evidence of a decreasing sink rate.

This paper provides a preliminary data set for dissolved nutrient abundance in the Dark Zone of the Greenland Ice Sheet. This 15-year marked darkening has since been attributed to glacier algae blooms, yet has not been accounted for in current melt rate models. We conclude that the dissolved organic phase dominates surface ice environments and that factors other than macronutrient limitation control the extent and magnitude of the glacier algae blooms.

With the recent publication of the IPCC special report on the 1.5 °C target and increased attention on carbon dioxide removal (CDR) technologies, we think it is time to advance from the current way of looking at specific strategies to a more holistic CDR perspective, since multiple "side effects" may lead to additional CO2 uptake into different carbon pools. This paper explores potential co-benefits between terrestrial CDR strategies to facilitate a maximum CO2 sequestration effect.

The observed decrease of oxygen and warming in the ocean may adversely affect marine ecosystems and their services. We analyse results from an Earth system model for the last millennium and the 21st century. We find changes in temperature and oxygen due to fossil fuel burning and other human activities to exceed natural variations in many ocean regions already today. Natural variability is biased low in earlier studies neglecting forcing from past volcanic eruptions and solar change.

How fast might the arctic treeline in northern central Siberia migrate northwards under current global warming? To answer this, we newly parameterized dispersal processes in the individual-based and spatially explicit model LAVESI-WIND based on parentage analysis. Simulation results show that northernmost open forest stands are migrating at an unexpectedly slow rate into tundra. We conclude that the treeline currently lags behind the strong warming and will remain slow in the upcoming decades.

Global forest resources are accounted for to establish their potential to sink carbon in woody biomass. Climate prediction models realize the effects of future global forest utilization rates, defined by population demand and its evolution over time. However, forest management approaches consider the supply side to realize a sustainable forest carbon stock and adapt the harvest rates to novel climate conditions. This study simulates such an adaptive sustained
yield approach.

The surface albedo time series CLARA-A2 SAL was used to study trends in the timing of the melting season of snow and preceding albedo value in Finland during 1982–2016 to assess climate change. The results were in line with operational snow depth data, JSBACH land ecosystem model, SYKE fractional snow cover and greening-up data. In the north a clear trend to earlier snowmelt onset, increasing melting season length, and decrease in pre-melt albedo (related to increased stem volume) was observed.

The paper revealed a potential structural deterioration induced by ocean acidification on the shells of an ecologically and economically important oyster, which is critical to forecasting the survival and production of edible oysters in the future ocean. Importantly, this is a multidisciplinary collaboration including aquaculture, crystallography, medical and materials science, which could be applied to other biomineral systems to hierarchically analyse the impact of ocean acidification.

Over the past decades temperate forests were a carbon (C) sink to the atmosphere. Yet the drivers of C uptake and how these affect the future carbon cycle remain uncertain. Our simulation and study revealed that the future C sink of central European forest landscapes is strongly driven by historic land use, while climate change reduces forest C uptake. Compared to land-use change, past natural disturbances (wind and bark beetles) have only marginal effects on the future carbon cycle.

Vegetation and soils strongly influence ground temperature in permafrost ecosystems across the Arctic and sub-Arctic. These effects will cause differences rates of permafrost thaw related to the distribution of tundra and boreal forests. As the distribution of forests and tundra change, the effects of climate change on permafrost will also change. We review the ecosystem processes that will influence permafrost thaw and outline how they will feed back to climate warming.

Invertebrate species of the Gullmar Fjord (Sweden) were exposed to four different treatments (high/low oxygen and low/high CO2) and respiration measured. Respiration responses of species of contrasting habitats and life-history strategies to single and multiple stressors was evaluated. Results show that the responses of the respiration were highly species specific as we observed both synergetic as well as antagonistic responses, and neither phylum nor habitat explained trends in respiration.

To understand ecological impacts of CO2-induced ocean acidification and temperature rise, a key question is if organisms become more vulnerable under multiple stressors. Here we tested heart rate and gene expression levels of a limpet under varying pCO2 and temperature. Results showed that while many individuals are more vulnerable to heat stress under high CO2 and increased temperature, some animals have the ability to alter their physiology to help them survive under future conditions.

Compared to the respiration process, few studies have examined soil carbon leaching possibly enhanced by extreme precipitation events (EPEs). We show that soil carbon leaching was much higher than CO2 loss through respiration under EPEs in grassland soils through incubation experiments. The soil carbon leaching process should be incorporated into soil carbon models when estimating carbon balance in grassland ecosystems, especially considering the projected increase in EPEs with climate change.

We describe the evolution of thaw slumps between 1952 and 2011 along the Yukon Coast, Canada, and calculate the contribution of the slumps to the carbon budget in this area. The number of slumps has increased by 73 % over the period. These slumps displaced more than 16 billion m3 of material and mobilized 146 t of carbon. This represents 0.6 % of the annual carbon flux released from shoreline retreat, which shows that the contribution of slumps to the nearshore carbon budget is non-negligible.

A vegetation model was used to reconstruct fire activity from 1901 to 2012 in relation to changes in lightning ignition, climate, and vegetation in eastern Canada's boreal forest. The model correctly simulated the history of fire activity. The results showed that fire activity is ignition limited but is also greatly affected by both climate and vegetation. This research aims to develop a vegetation model that could be used to predict the future impacts of climate changes on fire activity.

We observed that N : P supply ratios had the strongest effect on C : N : P stoichiometry, while temperature and pCO2 played more influential roles on PIC : POC and polyunsaturated fatty acid proportions in Emiliania huxleyi. Synergistic interactions indicated the enhanced effect of warming under nutrient deficiency and high pCO2. Simultaneous changes of elements and fatty acids should be considered when predicting future roles of E. huxleyi in biogeochemical cycles and ecological functions.

The negative effects of elevated temperature (31 °C) on larval settlement of P. damicornis was greatly tempered by diurnal temperature fluctuations, whilst diel oscillations in temperature reduced the heat stress on photo-physiology of coral recruits. Although elevated temperature greatly stimulated the growth of recruits, the daytime encounters with the maximum temperature of 33 °C in the fluctuating treatment elicited a notable reduction in calcification.

Solar radiation management (SRM) is suggested as a method to offset global warming and to buy time to reduce emissions. Here we use an Earth system model to project the impact of SRM on future ocean biogeochemistry. This work underscores the complexity of climate impacts on ocean primary production and highlights the fact that changes are driven by an integrated effect of many environmental drivers, which all change in different ways.

This study is the first to examine how permafrost slumping affects dissolved organic carbon (DOC) mobilization in landscapes dominated by glacial tills. Unlike in previous studies, we find that slumping is associated with decreased DOC concentrations in downstream systems – an effect that appears to occur via adsorption to fine-grained sediments. This work adds significantly to our understanding of varying effects of permafrost thaw on organic carbon mobilization across diverse Arctic regions.

The effects of C turnover time on ecosystem C storage have not been well explored, so we quantified the spatial variation in ecosystem C storage over time from changes in C turnover time and/or NPP. Our results showed that the terrestrial C release caused by the decrease in MTT only accounted for about 13.5 % of that due to the change in NPP uptake. However, the larger uncertainties in the spatial variation of MTT than temporal changes would lead to a greater impact on ecosystem C storage.

El Niño–Southern Oscillation (ENSO) has been identified as one of the main drivers for the interannual variability in eastern African rainfall. But we know little about its direct impact on vegetation and how it might change in the future. In this study, we quantified this relationship and predict its future under certain climate change scenarios. Results suggest that we need to consider an increase in future ENSO intensity to cover the full range of potential changes in vegetation responses.

Experiments that manipulate the temperature of plants and ecosystems are used to improve understanding of how they will respond to climate change. In logistically challenging locations passive warming using solar energy is the the only viable option for warming experiments. Unfortunately current passive warming approaches can only raise air temperature by about 1.5 °C. We have developed a novel approach that doubles the warming possible using solar energy and requires no power.

We studied the effects of summer heatwaves and drought on photosynthesis and isoprene emissions in black locust trees. While photosynthesis decreased, isoprene emission increased sharply during the heatwaves. Comparing isoprene emissions of stressed and unstressed trees at the same temperature, however, demonstrated that stressed trees emitted less isoprene than expected. This reveals that in order to predict isoprene emissions during heat waves, model parameters need to be re-evaluated.

There are large reserves of carbon within the permafrost which might be released to the atmosphere under global warming. Our models suggest this release may cause an additional global temperature increase of 0.005 to 0.2°C by the year 2100 and 0.01 to 0.34°C by the year 2300. Under climate mitigation scenarios this is between 1.5 and 9 % (by 2100) and between 6 and 16 % (by 2300) of the global mean temperature change. There is a large uncertainty associated with these results.

We conducted a field manipulation experiment by redistributing 67 % of dry-season rainfall into the wet season while keeping the annual rainfall unchanged in a subtropical forest. Soil net nitrification and N mineralization rates were decreased by 13–20 % in the dry season and increased by 50 % with an accelerated NO3 leaching in the wet season. Functional microbial gene abundance and microbial biomass were the main factors affecting the N-process responses to the rainfall seasonality changes.

Single-celled living calcareous planktic foraminifera data across the Mediterranean Sea suggest that stratification of the surface water column, food availability, temperature, and seawater carbonate chemistry are the main factors controlling their distribution and mass. Increasing temperature, salinity, surface ocean stratification, and trophic conditions could be the causes of reduced abundance, diversity and species-specific changes in calcification in planktic foraminifera.

We report regional-scale erosion of coral reef ecosystems in the Atlantic, Caribbean, and Pacific oceans determined by measuring changes in seafloor elevation. The magnitude of seafloor elevation loss has increased local sea level rise, causing water depths not predicted until near 2100, placing coastal communities at elevated and accelerating risk from hazards such as waves, storms, and tsunamis. Our results have broad implications for coastal resource and safety management.

We analyzed the evolution of the atmospheric CO2 mean annual cycle simulated during 1950–2300 under three scenarios designed to separate the effects of climate change, CO2 fertilization, and land use change. CO2 fertilization in boreal and temperate ecosystems drove mean annual cycle amplification over the NH midlatitudes during 1950–2300. Boreal and Arctic climate change drove high-latitude amplification before 2200, after which CO2 fertilization contributed nearly equally to amplification.

The use of 15N natural abundance of soil ammonium and nitrate demonstrates a clear shifting contribution from abiotic to biotic controls on N cycling along a 3200 km dryland transect in northern China, with a threshold at mean annual precipitation of 100 mm. Abiotic factors were the main driver below threshold, shown by the accumulation of atmospheric N and NH3 losses. In the area above threshold, soil N cycling was controlled mainly by biological factors, e.g., plant uptake and denitrification.

Savannas are extensive yet sensitive to variability in precipitation. We examined the relationship between climate phenomena and historical rainfall variability across Australian savannas using 16 climate indicies. Seasonal variation was most correlated with the Australian Monsoon Index, whereas interannual variability was related to a greater number of phenomena. Rainfall variability and the underlying climate processes driving variability are important.

Ocean acidification (OA) in the near future is affecting several marine organisms negatively. To increase our understanding of the effects we studied embryos and larvae of the great scallop. They were exposed to an increasing level of OA, from natural seawater to levels expected in 50–100 years from now. Larvae were negatively affected already after 2 days, and fed larva seemed as sensitive as unfed larvae after 7 days.
Adaption and acclimatization may counteract future OA effects on scallops.

Marine biota drives a number of climate-relevant mechanisms, not all of which are included in current Earth system models (ESMs) used for climate projections. We identify three classes of mechanisms and argue that, to adequately resolve these mechanisms and to ensure links to and feedbacks with other Earth system components, ESMs need to account for five marine organism groups.

The use of ocean gliders, a class of underwater vehicles for observing the ocean to understand biogeochemical and physical processes, has been pioneered in the North Sea as part of the coastal observatory COSYNA. Since gliders go slow, strong tidal currents are problematic for their navigation. To predict (